Optimizing Miniscrew Stability: A Finite Element Study of Titanium Screw Insertion Angles

Area of Science:

• Biomaterials Engineering
• Orthodontics
• Biomechanics
• Finite Element Analysis

Background:

• Orthodontic miniscrews provide anchorage but their biomechanical performance depends on insertion parameters.
• Understanding stress distribution at the titanium-bone interface is crucial for optimizing miniscrew stability and minimizing complications.

Purpose of the Study:

• To evaluate the influence of different miniscrew insertion angles (30°, 45°, 90°) on stress and displacement in alveolar bone using 3D FEA.
• To determine the optimal insertion angle for enhanced biomechanical stability and reduced stress concentration.

Main Methods:

• A 3D finite element model of the mandible was created with specific cortical and cancellous bone layers.
• Ti-6Al-4V miniscrews were virtually inserted at 30°, 45°, and 90° angles.
• A 2N horizontal orthodontic load was applied, and von Mises stress and displacement were analyzed using ANSYS Workbench.

Main Results:

• The 90° insertion angle resulted in the highest cortical bone stress (58.2 MPa) but the lowest displacement (0.023 mm).
• The 30° insertion angle produced lower stress (36.4 MPa) but greater displacement (0.052 mm).
• The 45° angle demonstrated a compromise with moderate stress (42.7 MPa) and displacement (0.035 mm), showing statistically significant differences (p < 0.001) across all groups.

Conclusions:

• Miniscrew insertion angle critically modulates biomechanical performance and bone response.
• A 45° insertion angle offers a balanced profile, combining adequate stability with reduced stress concentration, which is beneficial for clinical success.
• Surgical parameters, like insertion angle, are as vital as material properties for effective orthodontic anchorage.